a) Field of the Invention
The invention is directed to an arrangement for regulating the temperature of the sample space of a microscope, preferably for observing living cells (live cell imaging) with an objective turret carrying objectives, a sample holder serving to receive a sample, a heating or cooling insert with an incubator hood for managing the temperature of the sample holder, and an objective heating element or objective cooling element.
b) Description of the Related Art
In microscopic examination of living cells or tissue portions, it is increasingly required to adjust the specific living conditions of the specimen. Apart from taking into account the relative air humidity and the CO2 (carbon dioxide) content, this also includes regulating the temperature.
A known solution for keeping the temperature relatively constant is to use a heatable microscope stage. Different holder frames make it possible to adapt to all common sample receptacles. For example, if very low temperatures are required, the use of a temperature-controllable microscope stage in combination with a low-temperature controller is recommended.
Another known possibility for regulating temperature is carried out by means of a heated or cooled air flow which blows past the sample within a closed system (incubator) on the microscope and, together with the heatable or coolable microscope stage or a heating insert or cooling insert, supplies the required temperature for the sample.
An additional improvement in the temperature value in the observation area is achieved through the use of objective heating elements or objective cooling elements which are either connected directly to the objective or which supply heat or cold to the objective jacket in the form of an air flow. The objectives pass the temperature on to the sample via an immersion medium and the glass.
EP 1 051 064 B1, for example, describes a microscope in which the temperature of all of the objectives carried by the objective turret can be regulated simultaneously by a device which is arranged at the objective turret. Heating elements and cooling elements are provided for this purpose.
Another variant for heating objectives is shown in U.S. Pat. No. 5,410,429. In this case, the objective is heated in a defined manner by a heating loop which is placed around the objective jacket.
U.S. Pat. No. 3,343,018 describes electric objective heating elements which are integrated in the objective housing in the form of sleeves, for example.
All of the known solutions have the disadvantage that the amount of heat or cold which flows off in the areas remote of the front lens and even in the objective turret is so large that it is impossible to maintain a desired temperature or temperature constancy at the sample location without a very high expenditure with respect to the arrangement and regulating resources. Further, the thermal mass of the elements is very large so that a large amount of energy and time is required for changing the temperature.